Projector with scanning array light engine

ABSTRACT

A projector assembly includes a light emitting diode (LED) array, wherein the LED array has an array axis, wherein the LED array includes a plurality of LEDs arranged along the array axis, and wherein the plurality of LEDs are individually addressable. The projector assembly includes a rotatable actuator supporting the LED array, wherein the rotatable actuator has a rotation axis, and wherein the rotation axis and the array axis are parallel. The projector assembly includes a collimator positioned in optical communication with the LED array for collimating light emitted from the plurality of LEDs and a set of imaging optics positioned in optical communication with the collimator for focusing collimated light and forming a first image of the LED array at a distance, wherein the first image includes a first axis corresponding to the array axis and a second axis orthogonal to the rotation axis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/203,229 titled “PROJECTOR WITH SCANNING ARRAY LIGHT ENGINE,” filed onNov. 28, 2018, now U.S. Pat. No. 10,591,812, issued on Mar. 17, 2020,which is a continuation of U.S. patent application Ser. No. 15/828,005,filed Nov. 30, 2017, now U.S. Pat. No. 10,175,564, issued on Jan. 8,2019, titled “PROJECTOR WITH SCANNING ARRAY LIGHT ENGINE,” which claimsthe benefit of and priority to U.S. Provisional Patent Application No.62/429,003, titled “PROJECTOR WITH SCANNING ARRAY LIGHT ENGINE,” filedon Dec. 1, 2016, the disclosures of which are hereby incorporated byreference in their entireties for all purposes.

BACKGROUND

Image projectors can take many forms and use a variety of differenttechnologies, which range in both cost and complexity. For example, manycommon projectors used in office, conference, and home theater systemsfor video projection make use of 3 color light recombination (red,green, blue) for full color video. In liquid crystal display (LCD)projectors, light from a lamp is separated for each of the red, green,and blue components and passed through LCD gates including a pluralityof pixels for blocking or allowing the light to pass to generate anoutput light pattern. Digital light processing (DLP) and liquid crystalon silicon (LCOS) projectors use similar technology but respectivelymake use of micromirror and reflective active matrix liquid-crystalelements for generating the output light patterns instead of LCD gates.Due to the need for including optical elements for each of the 3 colors,these systems may be large and overly complex.

SUMMARY

The present disclosure relates to image projection. In particular, thepresent disclosure relates to a light emitting diode based imageprojector. Described herein are LED-based image projection systems andrelated projection methods. The systems and methods described hereinmake use of an array of LEDs, which output light that is projected usingoptical elements to form images at a distance. The size and/or number ofLEDs in the LED array may be reduced as compared to other LED projectiontechnologies by placing the LED array on a movable actuator, such as arotatable actuator, so that images of the LED array at differentpositions can be generated and combined to form a composite frame. Forexample, as the LED array is rotated as a function of time, a sequenceof images of the array can be generated. When done at a rapid enoughrate, a section by section composite frame, similar to a progressivescan frame, can be produced, and this process can be repeated to projecta video image.

In a first aspect, projector assemblies are provided. In a specificembodiment, a projector assembly comprises a light emitting diode (LED)array such as an LED array that has an array axis and includes aplurality of LEDs arranged along the array axis. The plurality of LEDscan be individually addressable. The projector assembly furthercomprises a movable actuator supporting the LED array such as arotatable actuator that has a rotation axis that is parallel to thearray axis or a translatable actuator that has a translation axisperpendicular to the array axis and a set of imaging optics positionedin optical communication with the LED array for forming a first image ofthe LED array at a distance. For example, the first image may include afirst axis corresponding to the array axis and a second axis orthogonalto the rotation axis or parallel to the translation axis. Optionally,output intensities of each of the plurality of LEDs are independentlycontrollable.

A variety of LED arrays are useful with the projector assemblesdescribed herein. For example, in some embodiments, the LED arraycomprises a one-dimensional LED array. Optionally, the LED arraycomprises a two-dimensional LED array. Useful LED arrays include LEDarrays having any practical number of elements. For example, in someembodiments, the LED array includes about 800 pixels, about 1024 pixels,about 1280 pixels, about 1440 pixels, about 1600 pixels, about 1920pixels, about 2560 pixels, about 3840 pixels, about 7680 pixels, or morethan about 7680 pixels. Optionally, each pixel corresponds to one ormore corresponding LEDs of the LED array.

In embodiments, the plurality of LEDs may generate light of any suitablecolor or wavelength. For example, in some embodiments, the pluralityLEDs include a first plurality of LEDs for producing light including afirst wavelength, a corresponding second plurality of LEDs for producinglight including a second wavelength different from the first wavelength,and a corresponding third plurality of LEDs for producing lightincluding a third wavelength different from the first wavelength and thesecond wavelength. In this way, full color images may be generated bycombining light from LEDs of three different colors. For example, insome embodiments, a set of three corresponding LEDs make up a pixel ofthe LED array. Optionally, a set of three corresponding LEDs includesone LED from the first plurality of LEDs, one LED from the secondplurality of LEDs, and one LED from the third plurality of LEDs. Otherconfigurations are possible, including where multiple LEDs from aplurality of LEDs are included in a set of LEDs making up a pixel.

Optionally, one of the first, second, or third wavelengths is about 650nm. Optionally, one of the first, second, or third wavelengths is about520 nm. Optionally, one of the first, second, or third wavelengths isabout 450 nm. Optionally, the light of the first, second, or thirdwavelength is or peaks at about 650 nm. Optionally, the light of thefirst, second, or third is or peaks at about 520 nm. Optionally, thelight of the first, second, or third is or peaks at about 450 nm. Othercolor/wavelength combinations are possible.

In some embodiments, the first plurality of LEDs, the second pluralityof LEDs, and the third plurality of LEDs include a same number of LEDs.However, in other embodiments, each of the first, second and thirdplurality of LEDs may include different numbers of LEDs. For example, insome embodiments, the first plurality of LEDs includes a differentnumber of LEDs as the second plurality of LEDs, the third plurality ofLEDs or both the second plurality of LEDs and the third plurality ofLEDs.

The LEDs in the array may be arranged according to any preferredconfiguration. For example, in some embodiments, the first plurality ofLEDs, the second plurality of LEDs, and the third plurality of LEDs areuniformly distributed along the array axis. Optionally, the firstplurality of LEDs are spatially grouped. Optionally, the secondplurality of LEDs are spatially grouped. Optionally, the third pluralityof LEDs are spatially grouped. Grouping of LEDs of a commonwavelength/color may be useful for some embodiments, includingembodiments where generation of spatially distinct single-color imagesis desired. In some embodiments, each LED in the second plurality ofLEDs is positioned adjacent to at least one corresponding LED in thefirst plurality of LEDs and at least one corresponding LED in the thirdplurality of LEDs.

LEDs included in the array may take on any suitable dimension. Forexample, in embodiments, each of the plurality of LEDs has a lateraldimension selected between about 0.5 μm and about 5 μm. The LED arrayitself may also take on any suitable dimension. In some embodiments, theLED array has a width axis orthogonal to the array axis, and wherein thewidth axis corresponds to the second axis. For example, in someembodiments, the LED array has a length along the array axis selectedbetween about 100 μm and about 10000 μm. Optionally, the LED array has alength along the width axis between about 0.5 μm and about 100 μm.

LEDs of any suitable switching speed may be used with the methods andassemblies described herein. It will be appreciated that a switchingspeed as fast as or faster than a desired frame rate for a video imagemay be useful with some embodiments. Optionally, each of the pluralityof LEDs are switchable at a frequency greater than or about 30 Hz,greater than or about 60 Hz, greater than or about 120 Hz, greater thanor about 240 Hz, greater than or about 1 kHz, greater or than about 1MHz, or between about 10 Hz and about 10 MHz.

In embodiments, supporting the LED array by a rotatable actuator isuseful to allow the LED array to generate outputs that may be spatiallyseparated. In embodiments, the rotatable actuator comprises amicroelectromechanical element. Optionally, the rotatable actuatorcomprises a piezoelectric element. The rotatable actuator may berotatable to any suitable number of positions or to any suitable angle.In some embodiments, the rotatable actuator is controllable to aplurality of distinct positions parallel to the array axis includingabout 600, about 768, about 720, about 800, about 900, about 1024, about1200, about 1080, about 1440, about 1600, about 2160, about 4230, morethan about 4230 distinct positions parallel to the array axis, orbetween about 100 and about 100000 positions parallel to the array axis.

Optionally, the rotatable actuator has a length along the array axisthat is about equal to a lateral dimension of the LED array along thearray axis. Optionally, the LED array has a width axis orthogonal to thearray axis. In embodiments, the rotatable actuator has a rotation anglearound the rotation axis corresponding to an angle between an opticalaxis of the collimator or the set of imaging optics and the width axis,such as a rotation angle that is continuously or discretely controllablebetween about 45° and about +135°. It will be appreciated that, in someembodiments, rotation of the rotatable actuator about the rotation axiscauses a displacement of the LED array orthogonal to the rotation axis.

In embodiments, supporting the LED array by a translatable actuator isuseful to allow the LED array to generate outputs that may be spatiallyseparated. In embodiments, the translatable actuator comprises amicroelectromechanical element. Optionally, the translatable actuatorcomprises a piezoelectric element. The translatable actuator may betranslatable to any suitable number of positions. In some embodiments,the translatable actuator is controllable to a plurality of distinctpositions parallel to the array axis including about 600, about 768,about 720, about 800, about 900, about 1024, about 1200, about 1080,about 1440, about 1600, about 2160, about 4230, or more than about 4230distinct positions parallel to the array axis.

Optionally, the translatable actuator has a length along the array axisthat is about equal to a lateral dimension of the LED array along thearray axis. Optionally, the LED array has a width axis orthogonal to thearray axis. In embodiments, the translatable actuator is translatablealong the translation axis continuously or discretely.

In a specific embodiment, the LED array outputs a one-pixel wide outputand rotation of the LED array about the rotation axis or translation ofthe LED array along the translation axis generates a two-dimensionaloptical output corresponding to a composite of multiple one-pixel wideoutputs. For example, the two-dimensional optical output may be imagedby the set of imaging optics to generate the first image.

Optionally, the set of imaging optics includes a collimator, which maybe useful for generating collimated light from the LED array. Inembodiments, the collimator comprises a lens or a mirror. Optionally,the collimator is positioned to receive light generated by the pluralityof LEDs and output parallel light rays. In some embodiments, thecollimator comprises an optical element that is contoured to outputparallel or substantially parallel light rays from the plurality of LEDsas the rotatable actuator is moved, such as about the rotation axis oralong a translation axis. Optionally, the collimator comprises aplurality of collimation elements each positioned to receive lightgenerated by a subset of the plurality of LEDs and output parallel orsubstantially parallel light rays.

In embodiments, the collimator may include optical coatings or filters.For example, in some embodiments, the collimator includes a reflectiveor anti-reflective coating. Optionally, the collimator includes apolarizer.

Other optical elements are useful with the set of imaging optics. Forexample, in some embodiments, the set of imaging optics includes one ormore lenses, mirrors, or filters. Optionally, the set of imaging opticsfocuses light generated by the plurality of LEDs to a focal length ofbetween about 1 mm and 1 m. Optionally, optical elements of the set ofimaging optics includes one or more reflective or anti-reflectivecoatings or a polarizer.

In some embodiments, a projector assembly may include one or moreadditional LED array for generating one or more additional images. Suchimages may optionally be spatially offset and may correspond to the sameor different output intensities. In some embodiments, a projectorassembly may further comprise a second LED array, such as a second LEDarray that has a second array axis and that includes a second pluralityLEDs, such as individually addressable LEDs, that are arranged along thesecond array axis; and a second movable actuator supporting the secondLED array, such as a rotatable actuator that has a second translationaxis that is parallel to the second array axis or a translatableactuator that has a second translation axis that is perpendicular to thearray axis. In some embodiments, the second LED array is positioned inoptical communication with the set of imaging optics. For example, thesecond LED array may be positioned in optical communication with acollimator, such as a collimator that collimates light emitted from thesecond plurality of LEDs. Optionally, the set of imaging optics forms asecond image of the second LED array at a distance, such as a secondimage that includes a third axis corresponding to the second array axisand a fourth axis orthogonal to the second rotation axis or parallel tothe second translation axis.

Various configurations of the first LED array and the second LED arrayare possible. For example, the second array axis and the first arrayaxis may optionally be parallel. Optionally, the second array axis andthe first array axis may be perpendicular. Depending on the particularconfiguration, the LED array and the second LED array may optionallyhave different lateral dimensions and/or include different numbers ofLEDs.

In some embodiments, the first image generated by the first LED arraycorresponds to a first depth field and the second image generated by thesecond LED array corresponds to a second depth field. In this way, theprojector assembly may generate multiple images of a same scene, butfeaturing different depth planes, and be useful for generating an imagethat may have depth information. If using two projector assemblies, eachassembly may generate an image from a slightly different perspective,making the depth fields useful for generation of a three dimensionaldisplay.

In some embodiments, the first image and the second image at leastpartially spatially overlap. In this way, the two images may complementone another, and may, for example, be useful for improving a videorefresh rate. Optionally, the first image and the second image arespatially offset.

In another embodiment, multiple images may be generated using a singleLED array, such as multiple spatially offset images. For example, insome embodiments, a projector assembly may further comprise atranslation stage, for generating a relative translation between the LEDarray and the set of imaging optics. In this way, the LED array may betranslated to a second position so that a second image may be generated.Optionally, the translation stage comprises a microelectromechanicalelement. Optionally, the translation stage comprises a piezoelectricelement. In embodiments, the relative translation is along an axisperpendicular to the rotation axis or parallel to the translation axis.It will be appreciated that the relative translation may be useful forforming a second image of the LED array in a translated position.

Different configurations may be useful for generating the relativetranslation. For example, in some embodiments, translation stage is inmechanical communication with the rotatable actuator for translating themovable actuator and the LED array relative to the set of imagingoptics. Optionally, the translation stage is in mechanical communicationwith the collimator for translating the set of imaging optics relativeto the LED array.

Other components may be useful with the projector assemblies and methodsdescribed herein. For example, one or more waveguides or diffractiveelements may be used, such as to aid in a viewer seeing the imagesgenerated by the projector assembly. For example, in some embodiments, aprojector assembly may further comprise a first diffractive opticalelement positioned in optical communication with the set of imagingoptics for receiving the first image of the LED array and generatingfirst diffracted light; a waveguide positioned in optical communicationwith the first diffractive optical element for receiving the firstdiffracted light and transmitting the first diffracted light by totalinternal reflection; a second diffractive optical element positionedwithin or on the waveguide for generating second diffracted light fromthe first diffracted light; and a third diffractive optical elementpositioned in optical communication with the second diffractive elementfor third generating diffracted light from the second diffracted light.Additional details regarding the use of waveguides and diffractiveelements for generating a display of the images generated by a projectorassembly may be found in U.S. Provisional Application 62/377,831, filedAug. 22, 2016, which is hereby incorporated by reference in itsentirety.

In another embodiment, a projector assembly may comprise a lightemitting diode (LED) array, such as an LED array has an array axis andincludes a plurality of LEDs, which may be individually addressable,arranged along the array axis; a movable actuator supporting the LEDarray, such as a rotatable actuator that has a rotation axis that isparallel to the array axis or a translatable actuator that has atranslation axis that is perpendicular to the array axis; a set ofimaging optics positioned in optical communication with the LED arrayfor collecting light emitted by the plurality of LEDs and forming one ormore images of the LED array at a distance, such as one or more imagesthat include a first axis corresponding to the array axis and a secondaxis orthogonal to the rotation axis or parallel to the translationaxis.

In some embodiments, the set of imaging optics may not include acollimator. When a collimator is not included, directional informationfor light generated by the LED array may be retained in the projectedimage, which may be useful for some embodiments. For example, it will beappreciated that retaining directional information may be useful forlight field applications, where direction, phase, and/oramplitude/intensity may be retained in order to generate athree-dimensional or four-dimensional image. Optionally, the pluralityof LEDs each have independently controllable output amplitudes.Optionally, the set of imaging optics includes one or more electro-opticelements for controlling and/or retaining a phase of light emitted bythe plurality of LEDs. Optionally, the set of imaging optics includesone or more elements for controlling and/or retaining directionalinformation for light emitted by the plurality of LEDs. Optionally, arotatable actuator controls a direction of light generated by the LEDarray.

In another aspect, methods are described for generating images, such asby using a projector assembly described herein. In one example, a methodembodiment of this aspect may comprise creating a first partial imageusing a projector assembly, moving a movable actuator of the projectorassembly to move the LED array of the projector assembly to a secondposition; and creating a second partial image using the projectorassembly. Optionally, the first partial image and the second partialimage are spatially offset and together form a first composite image.

In some embodiments, the movable actuator comprises a rotatableactuator. In some embodiments, a method of this aspect may furthercomprise rotating the rotatable actuator one or more times and creatingone or more corresponding additional partial images, such as where theone or more corresponding additional partial images are each spatiallyoffset from other partial images and together form the first compositeimage. Optionally, rotating the rotatable actuator includes rotating therotatable actuator by a discrete angle. Optionally, rotating therotatable actuator includes rotating the rotatable actuatorcontinuously.

In some embodiments, the movable actuator comprises a translatableactuator. In some embodiments, a method of this aspect may furthercomprise translating the translatable actuator one or more times andcreating one or more corresponding additional partial images, such aswhere the one or more corresponding additional partial images are eachspatially offset from other partial images and together form the firstcomposite image. Optionally, translating the translatable actuatorincludes translating the translatable actuator by a discrete distance.Optionally, translating the translatable actuator includes translatingthe translatable actuator continuously.

In some embodiments, creating the first partial image, moving themovable actuator, and creating the second partial image are repeated ata rate of about 30 Hz, about 60 Hz, about 120 Hz, about 240 Hz, greaterthan about 240 Hz, or between about 10 Hz and 480 Hz. In this way,methods of this aspect may be used for generating video images.

Optionally, the projector assembly may include a translation stage forgenerating relative translations between the LED array and the set ofimaging optics. In some embodiments, a method of this aspect may furthercomprise generating a relative translation between the LED array and theset of imaging optics such that the LED array is translated to atranslated relative position; creating a third partial image, such as bygenerating a third light using the LED array at the translated relativeposition and imaging the third light by the set of imaging optics toform the third partial image; moving the movable actuator to move theLED array to a translated and moved relative position; creating a fourthpartial image, such as by generating a fourth light using the LED arrayat the translated and moved relative position and imaging the fourthlight by the set of imaging optics to form the fourth partial image, sothat the third partial image and the fourth partial image are spatiallyoffset and together form a second composite image. Optionally, the firstcomposite image corresponds to a first depth field and the secondcomposite image corresponds to a second depth field.

Optionally, the projector assembly may include two or more LED array,such as two or more LED array each having independent array axes, andindependently include a pluralities of LEDs, where each LED element isindividually addressable, arranged along the respective array axes; andtwo or more movable actuator each respectively supporting an LED array.Each LED array may be positioned in optical communication with a set ofimaging optics so that images of each LED array may be formed at adistance.

Optionally, a method of this aspect may comprise creating a thirdpartial image, such as by generating third light using a second LEDarray at a third position, and imaging the third light by the set ofimaging optics to form the third partial image; moving a second movableactuator to move the second LED array to a fourth position; creating afourth partial image, such as by generating fourth light using thesecond LED array at the fourth position and imaging the fourth light bythe set of imaging optics to form the fourth partial image. Optionally,the third partial image and the fourth partial image are spatiallyoffset and together form a second composite image. Again, it will beappreciated that different composite images may correspond to differentdepth fields.

Optionally, projector assemblies useful with the methods describedherein may further comprise a first diffractive optical elementpositioned in optical communication with the set of imaging optics forreceiving the first image of the LED array and generating diffractedlight; a waveguide positioned in optical communication with the firstdiffractive optical element for receiving the diffracted light andtransmitting the diffracted light by total internal reflection; a seconddiffractive optical element positioned within or on the waveguide forgenerating diffracted light; and a third diffractive optical elementpositioned in optical communication with the second diffractive elementfor generating diffracted light. Optionally, a method of this aspect mayfurther comprise diffracting at least a portion of the first compositeimage using the first diffractive optical element to generate adiffracted image, such as a diffracted image that is received by thewaveguide; transmitting the diffracted image using the waveguide;diffracting at least a portion of the diffracted image using the seconddiffractive optical element to generate an expanded image; anddiffracting at least a portion of the expanded image using the thirddiffractive optical element to generate an output image. In this way,images generated by the projector assembly may be displayed for aviewer.

In another aspect, projector assemblies are provided. In an embodiment,a projector assembly comprises a LED array, wherein the LED array has anarray axis, wherein the LED array includes a plurality of LEDs arrangedalong the array axis, and wherein the plurality of LEDs are individuallyaddressable. The projector assembly further comprises a rotatableactuator supporting the LED array, wherein the rotatable actuator has arotation axis, and wherein the rotation axis and the array axis areparallel, and a set of imaging optics positioned in opticalcommunication with the LED array for collecting light emitted by theplurality of LEDs and forming one or more images of the LED array at adistance, wherein the one or more images include a first axiscorresponding to the array axis and a second axis orthogonal to therotation axis. Optionally, the output amplitude of the plurality of LEDscan be independently controllable.

Optionally, the set of imaging optics may further comprise one or moreelectro-optic elements for controlling a phase of light emitted by theplurality of LEDs. The set of imaging optics may further comprise one ormore elements for retaining directional information for light emitted bythe plurality of LEDs. Optionally, the rotatable actuator can control adirection of light generated by the LED array.

Additional features, benefits, and embodiments are described below inthe detailed description, figures, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A, FIG. 1B, FIG. 1C, and FIG. 1D illustrate example LED arraysaccording to one embodiment.

FIG. 2A, FIG. 2B, and FIG. 2C illustrate rotation of an LED arrayaccording to an embodiment.

FIG. 3A provides a schematic illustration of a projector assembly in anx-z plane according to one embodiment.

FIG. 3B provides a schematic illustration of a projector assembly in anx-z plane according to one embodiment.

FIG. 3C provides a schematic illustration of a projector assembly in ay-z plane according to one embodiment.

FIG. 3D provides a perspective view schematic illustration of aprojector assembly according to one embodiment.

FIG. 4 provides a schematic illustration of an LED-based projectorassembly including two LED arrays for generation of images according toone embodiment.

FIG. 5A and FIG. 5B illustrate rotation and translation of an LED arrayaccording to one embodiment.

FIG. 5C provides a schematic illustration of an LED-based projectionsystem that uses rotation and translation for generation of imagesaccording to one embodiment.

FIG. 6A provides a perspective view of multiple LED arrays according toone embodiment.

FIG. 6B provides a schematic illustration of multiple LED arrays in thex-y plane according to one embodiment.

FIG. 6C provides a schematic illustration of an LED-based projectorassembly including multiple LED arrays in the y-z plane according to oneembodiment.

FIG. 6D provides a schematic illustration of an LED-based projectorassembly including multiple LED arrays in the x-z plane according to oneembodiment.

FIG. 7A illustrates an example LED array including distinct sets of LEDsof three different colors according to one embodiment.

FIG. 7B illustrates components of a projector assembly for generatingspatially distinct images of distinct sets of LEDs according to oneembodiment.

FIG. 8 provides an overview of an example image projection methodaccording to one embodiment.

FIG. 9 provides an overview of an example image projection methodaccording to one embodiment.

FIG. 10 provides an overview of imaging light from an LED array whileretaining directional information according to one embodiment.

DETAILED DESCRIPTION

The projector systems and methods described herein use an LED arrayincluding a plurality of LEDs arranged along an axis. The LED array maybe supported by a movable actuator in order to move the LED array andgenerate images of the LED array in different positions. In someembodiments, the movable actuator is a rotatable microelectromechanicalactuator. As the actuator is rotated, the LED array is moved todifferent physical positions. When light generated by the LED array isimaged using a set of imaging optics, spatially distinct images of thelight from the LED array may be formed corresponding to the differentphysical positions of the LED array when moved by the actuator.

By controlling the rotation of the actuator and the timing and output ofthe LEDs in the LED array, video images may be generated. For example, afirst image partial generated by the LED array at a first position maybe generated. When the LED array is rotated to a second position and asecond partial image may be generated by the LED array, where the secondpartial image may be offset from the first partial image both in spaceand time. This process may be repeated as the LED array is rotatedthrough a fixed number of positions to generate a full image frame andthen the process repeated in order to generate a video image havingmultiple frames.

The rotation of the LED array may also be a continuous process, ratherthan a discrete set of positions. The timing of output of the LEDelements in the array may be controlled in order to create the partialimages which together will make up a full image frame. Again, theprocess may be repeated in order to generate a video image havingmultiple frames.

The light from the LED array may be projected at a distance using anoptical imaging system. For example, an optical imaging system mayinclude one or more lenses, mirrors, collimators, and the like. Use of acollimator may be valuable for some embodiments, as some LEDs maygenerate a divergent output and so may benefit from collimation in orderto project a sharp image at a distance.

FIGS. 1A-1D provide schematic illustrations of LED arrays 100A, 100B,100C, and 100D. Each of the LED arrays 100A-100D include a plurality ofindividually addressable LED elements arranged along an axis, such asthe x-axis as shown in FIG. 1A. In FIG. 1A, the LED array 100A includesLED elements 105A positioned on a supporting structure 110A, which maycorrespond to a movable actuator, such as a rotatable or translatableactuator. Each LED element 105A may correspond to a pixel element of aprojected image. Although LED array 100A includes 10 LED elements 105,it will be appreciated that an LED array may include any number of LEDelements, as desired, in order to generate an image with a desiredresolution. For example, each pixel in a projected image may correspondto an LED element or a plurality of LED sub-elements.

In addition, an LED array may include a single line of LED elements(e.g., a 1-dimensional array) or multiple lines of LED elements (e.g., a2-dimensional array), with any practical number of rows for generatingimages based on the movement of the LED array, such as by a rotatableactuator. For example, two or more rows of LED elements may be used,such as three rows, four rows, five rows, six rows, seven rows, eightrows, nine rows, or ten rows.

A variety of rotatable actuators may be used with the projection systemsand methods described herein, including microelectromechanical rotationactuators, a magnetic-drive rotation actuator, an electric-driverotation actuator, a cantilever-based rotation actuator, etc. It will beappreciated that, although the present description makes reference torotatable actuators for moving an LED array for generation of atwo-dimensional image, other movable actuators may be used to similarlygenerate a two-dimensional image. For example, in some embodiments,instead of a rotatable actuator, a translatable actuator may be used. Insome embodiments a translatable actuator comprises amicroelectromechanical actuator, a magnetic-drive actuator, anelectric-drive actuator, a piezoelectric actuator, etc.

The LED elements in the LED array may take on any suitable shape,dimension, and arrangement. For example, the LED elements may havesquare, rectangular, or round output surfaces. The LED elements may havelateral dimensions ranging from about 0.5 μm to about 100 μm, dependingon the desired configuration and output. In some specific embodimentsthe lateral dimensions between 0.5 μm and about 5 μm. The LED elementsmay be arranged in a side by side (strip) configuration, a checkeredconfiguration, a PenTile Matrix configuration, etc.

In FIG. 1B, the LED array 100B includes LED elements 105B positioned ona supporting structure 110B, which may correspond to a movable actuator,such as a rotatable or translatable actuator. Each LED element 105B maycorrespond to a pixel element of a projected image and may includesub-elements 115, 116, and 117, which may correspond to three differentcolor LED elements (e.g., red, green, blue) arranged in a vertical stripconfiguration in order to generate a full color pixel element, wherethree adjacent LED elements correspond to sub-pixel elements andtogether make up a single pixel element. Although 30 LED sub-elementsare depicted, it will be appreciated that any number of LED elements orsub-elements may be included, as desired.

In FIG. 1C, the LED array 100C includes LED elements 105C positioned ona supporting structure 110C, which may correspond to a movable actuator,such as a rotatable or translatable actuator. Each LED element 105C maycorrespond to a pixel element of a projected image and may includesub-elements 120, 121, and 122, which may correspond to three differentcolor LED elements (e.g., red, green, blue) arranged in a horizontalstrip configuration in order to generate a full color pixel element.Again, it will be appreciated that any number of LED elements orsub-elements may be included, as desired.

In FIG. 1D, the LED array 100D includes LED elements 105D positioned ona supporting structure 110D, which may correspond to a movable actuator,such as a rotatable or translatable actuator. Each LED element 105D maycorrespond to a pixel element of a projected image and may includesub-elements, which may correspond to three or more different color LEDelements (e.g., red, green, blue, white) arranged in a checkeredconfiguration in order to generate a full color pixel element. Again, itwill be appreciated that any number of LED elements or sub-elements maybe included, as desired. It will further be appreciated that thesub-pixel configurations illustrated in FIGS. 1B-1D are merely examplesand that other sub-pixel configurations may be possible or desirable,and the use of sub-pixel rendering algorithms may also be possible ordesirable.

In embodiments, an LED array may include any practical number of LEDelements in order to project an image of a desired first resolution. Forexample, an LED array having 1024 elements, where each element mayinclude multiple sub-elements, may correspond to an image having a firstresolution including lines of 1024 pixels. Other examples are possible,including, but not limited to, LED arrays having 600 elements, 720elements, 768 elements, 800 elements, 900 elements, 1080 elements, 1200elements, 1280 elements, 1440 elements, 1600 elements, 1920 elements,2160 elements, 2560 elements, 3850 elements, 4230 elements, or 7680elements. It will be appreciated that these numbers of elements aremerely examples and may correspond to common digital image resolutions.

FIGS. 2A-2C depict an LED array 200 rotated among various positionsaround an axis of rotation 205. As illustrated, axis of rotation 205 maybe parallel to the x-axis, as depicted in FIG. 2A. It will beappreciated that the axis of rotation may be positioned at any suitablelocation proximal to the LED array, such as below the LED array, and maybe dictated by the specific geometry and configuration of the supportingstructure and rotatable actuator used. The LED array 200 is depicted ashaving an array axis 210 parallel to the axis of rotation 205 and anaxis 215 orthogonal to the array axis. Axis 220 may correspond, forexample, to an optical axis of a set of optical elements used forprojecting light generated by LED array 200, and may be parallel to thez-axis as illustrated in FIG. 2A. FIG. 2A is depicted as a configurationwhere axis 220 and axis 215 are perpendicular.

In some embodiments, two axes or object referred to as being parallelmay correspond to the two axes or objects being absolutely parallel orsubstantially parallel, such as arranged to within about ±5 degrees ofbeing absolutely parallel. In some embodiments, two axes or objectsreferred to as being perpendicular or orthogonal may correspond to thetwo axes or objects being arranged at exactly 90 degrees with respect toeach other or substantially perpendicular or substantially orthogonal toone another, such as arranged to between about 85 and about 95 degreeswith respect to each other. In some embodiments, when two objects oraxes are arranged substantially parallel, substantially perpendicular,or substantially orthogonal, the utility may not be impacted and stillmay provide for a similar utility as though the objects were exactlyparallel, exactly perpendicular, or exactly orthogonal.

For example, although the axis of rotation 205 and array axis 210 aredepicted in FIGS. 2A-2C as being exactly parallel, the LED array 200would also be useful for operating according to the principles describedherein in order to generate composite images upon rotation of the LEDarray 200 about the axis of rotation 205 if the axis of rotation 205 andthe array axis 210 were substantially parallel.

It will further be appreciated that the term “about” as used hereinindicates that values proximate to a stated value may be included orused without departing from the spirit of the invention. Optionally,“about” may indicate that a value may include values within 10% of astated value. As one example, “about 10” may correspond to between 9 and11, inclusive.

FIG. 2B shows LED array 200 rotated in a first direction 225 about theaxis of rotation 205, such that an angle between axis 215 and axis 220is more than 90 degrees. FIG. 2C shows LED array 200 rotated in a seconddirection 230 about the axis of rotation 205 opposite to the firstdirection, such that an angle between axis 215 and axis 210 is less than90 degrees, such as between 0 degrees and 90 degrees. It will beappreciated that, in some embodiments, a rotatable actuator providingthe rotation of LED array 200 about the axis rotation may be configuredto provide a continuous rotation, such that an angle between axis 215and axis 220 may be continuously adjustable, such as to any value. Inother embodiments, the rotatable actuator may be configured to providestepped rotation, such that an angle between axis 215 and axis 220 maybe discretely adjustable only to particular values.

In some embodiments, LED array may be rotated about the array axisbetween two maximum rotation amounts, such as a first maximum amountalong a first rotation direction, such as rotation direction 225, and asecond maximum amount along a second rotation direction, such asrotation direction 230. In some embodiments, the rotation may occurcontinuously or in discrete steps. Optionally, the LED array may berotated along the first direction in discrete steps to the first maximumand then quickly rotated along the second direction to the secondmaximum in one step and again rotated discrete steps along the firstdirection to the first maximum. In this way, a one-directionalprogressive rotation may be established. Optionally, the LED array maybe rotated along the first direction in discrete steps to the firstmaximum and then rotated along the second direction in discrete steps tothe second maximum and then this process repeated. In this way, atwo-directional progressive rotation may be established. Depending onthe particular projection configuration, these or other rotation schemesmay be used to generate composite images by rotating the LED array andcontrolling the timing and output of the individual LED elements togenerate a desired image.

Using the three positions depicted in FIGS. 2A-2C, an image with threerows of pixels may be generated. Any number of positions may be usedwith the systems and methods disclosed herein. In some embodiments, therotation of the LED array 200 about axis of rotation 205 betweenpositions will have a magnitude sufficient for spatially separating thelight projected from the LED array in each position. For example, thelight from the LED array in the position corresponding to FIG. 2A may bea central pixel line, while the light from the LED array in the positioncorresponding to FIG. 2B may be offset above the central pixel line andthe light from the LED array in the position corresponding to FIG. 2Cmay be offset below the central pixel line. In this way, distinct rowsof pixels may be generated using the systems and methods describedherein.

In some embodiments, however, the LED array may be rotated an amountsuch that the images generated may at least partially overlap. Such aconfiguration may be useful for some embodiments, such as wheresub-pixel rendering may aid in the creation of image details. Inaddition, for some LED array configurations, such as the horizontalstrip configuration shown in FIG. 1C, overlapping pixel lines may beuseful for improving the resolution of the output image along adirection perpendicular to the axis of rotation. In some embodiments,the size of a pixel element may correspond to the total size of a set ofsub-pixel elements, such as a lateral dimension of the LED elements ofthe LED array 200. In other embodiments, the size of a pixel element maycorrespond to the size of an individual sub-pixel element. For example,using the LED array 110C shown in FIG. 1C, the top line of LEDsub-elements 120 first may be used to generate a line of red pixeloutputs for a particular pixel line. Then, the LED array 110C may berotated such that green light from the middle line of LED sub-elements121 may be projected to generate a line of green pixel outputs havingthe same spatial position as the red pixel outputs previously generated.Finally, the LED array 110C may be rotated such that blue light from thebottom line of LED sub-elements 122 may be projected to generate a lineof blue pixel outputs having the same spatial position as the red pixeloutputs and green pixel outputs previously generated. In this way, theoverall image resolution along the direction perpendicular to the axisof rotation may be improved by a factor of 3 as compared to theconfiguration where the pixel elements do not overlap.

In embodiments, the LED array may be rotatable to any practical numberof positions in order to project an image of a desired secondresolution. For example, a rotatable actuator may be rotatable to about1280 positions, so that each position may provide a partial image inorder for the full image to have a resolution including 1280 lines ofpixels. Other examples are possible, including, but not limited to,where a rotatable actuator is rotatable to 600 positions, 720 positions,768 positions, 800 positions, 900 positions, 1080 positions, 1200positions, 1280 positions, 1440 positions, 1600 positions, 1920positions, 2160 positions, 2560 positions, 3850 positions, 4230positions, or 7680 positions. It will be appreciated that these numbersof positions are merely examples and may correspond to common digitalimage resolutions.

In other embodiments, the LED array may be continuously rotatableinstead of discretely rotatable. In order to project an image withdifferent lines of pixels, the elements of the LED array may have theiroutputs controlled. For example, when the LED array is in a firstposition, the output of the LED array may be controlled to project afirst line of pixels corresponding to a first portion of a full frame.As the LED array is rotated, the output of the LED array may be timed sothat when the LED array is in the appropriate position, a second outputof the LED array may be controlled to project a second line of pixelscorresponding to a second portion of a full frame. This process may berepeated to generate an full image frame of more lines of pixels. Inthis way, the LED array may be used to generate an image of a desiredresolution.

FIG. 3A provides a schematic illustration of an example projectorassembly 300A in an x-z plane. Projector assembly 300A includes LEDarray 305A and set of imaging optics 310A. Set of imaging optics 310Aincludes a collimator 315A and five focusing lenses 320. Collimator 315Amay be used to parallelize light generated by LED array 305A, which maybe divergent upon emission by the LED array 305A. Set of imaging optics310A may be used to generate an image 325A of LED array 305A. It will beappreciated that the LED array 305A may be rotated about a rotation axisthat is parallel to the x-axis in order to generate a two-dimensionalimage of LED array 305A.

FIG. 3B provides a schematic illustration of another example projectorassembly 300B in an x-z plane. Projector assembly 300B includes LEDarray 305B and set of imaging optics 310B. Set of imaging optics 310Bincludes five focusing lenses 320 and does not include a collimator.Collimation elements 315B and 316B are optionally attached to and/orpart of LED array 305B to individually parallelize the light generatedby the LED elements of LED array 305B. Individual collimation elements315B may optionally be used to collimate light from individual LEDelements. Shared collimation elements 316B may optionally be used tocollimate light from multiple LED elements, such as from two or moreindividual LED elements or multiple LED sub-elements. Set of imagingoptics 310B and collimation elements 315B and 316B may be used togenerate an image 325B of LED array 305B. It will be appreciated thatthe LED array 305B may be rotated about a rotation axis that is parallelto the x-axis in order to generate a two-dimensional image of LED array305B.

FIG. 3C provides a schematic illustration of projector assembly 300A ina y-z plane. Here, the rotation of the LED array 305A about an axisparallel to the x-axis is depicted, showing two discrete positions ofthe LED array 305A. Image 325A accordingly shows two discrete componentscorresponding to the two discrete positions of LED array 305.

FIG. 3D provides a perspective view schematic illustration of projectorassembly 300A, showing x-, y-, and z-axes. Here, the rotation directionof the LED array 305A about an axis parallel to the x-axis is depicted,but discrete positions of the LED array 305A are not shown. Image 325Ashows how discrete components may together make up a two-dimensionalcomposite image.

It will be appreciated that although the LED array 305A is shown as aone-dimensional array, LED array 305A may be a two dimensional array,such as an array that includes two or more rows and any number of LEDelements in each row (e.g., 10 elements as shown in FIG. 3D). Aconfiguration including a two dimensional array may be operatedaccording to the same principles described herein to generate a twodimensional image, but half as many different positions for the LEDarray may be required for a two-row array as a one-row array forgeneration of an image of the same number of pixels. Alternatively,overlapping pixel sub-elements may be generated, as described above.

In some embodiments, it may be desirable to generate two or morespatially separate images using a single projection system. In oneembodiment, multiple image generation may be provided by using twoseparate LED arrays. In another embodiment, multiple image generationmay be provided by using one LED array and translating the LED array toseparate positions in order to generate the multiple images. In someembodiments, generating different images may be useful for generating afirst image representing a first depth plane and a second imagerepresenting a second depth plane, such as for use in generation of athree-dimensional image.

FIG. 4 provides a schematic illustration of an example projectorassembly 400 in a y-z plane for generating multiple images. Projectorassembly 400 includes LED array 405A and 405B and set of imaging optics410. Set of imaging optics 410 includes a collimator 415 and fivefocusing lenses 420. Collimator 415 may be used to parallelize lightgenerated by LED arrays 405A and 405B, which may be divergent uponemission by the LED arrays 405A and 405B. Set of imaging optics 410 maybe used to generate an first image 425A of LED array 405A and a secondimage 425B of LED array 405B. Outputs from each LED element of LED array405A and 405B may be independently controllable. Each of LED array 405Aand 405B may be independently rotatable.

FIG. 5A and FIG. 5B provide perspective view schematic illustrationsshowing translation of a single LED array 505 for use in generatingmultiple images. In FIG. 5A, LED array 505 is translated along anegative y direction and then the LED array is rotated about an axis ofrotation for generation of a first image. In FIG. 5B, LED array 505 istranslated along a positive y direction and then the LED array isrotated about an axis of rotation for generation of a second image.Different translatable actuators may be useful for translating the LEDarray 505. For example, a linear translatable microelectromechanicalactuator may be used to translate the LED array 505 between discretepositions. Alternatively or additionally, a piezoelectric actuator maybe used to translate the LED array 505 between discrete positions. Itwill be appreciated that translation of the LED array 505 may alsoresult in the translation of any rotatable actuator providing thedepicted rotation. Thus, the LED array and rotatable actuator supportingthe LED array may all be provided on a translation stage using one ormore translation actuators, for example.

FIG. 5C provides a schematic illustration an example projector assembly500 in a y-z plane for generating multiple images making use of LEDarray 505 and accompanying translation components. Similar to the otherprojection systems described herein, projector assembly 500 includes aset of imaging optics 510. LED array 505 is supported by a translatableactuator 515 in order to translate 520 the LED array 505 betweendifferent positions. As illustrated, LED array is used in a firstposition to generate a first two-dimensional image 525A and translatedto a second position where it is used to generate a secondtwo-dimensional image 525B.

FIG. 6A-6D illustrate an alternative embodiment including multiple LEDarrays 601, 602, and 603. In this embodiment, LED arrays 602 and 603 areoriented perpendicular to LED array. FIG. 6A shows a perspective view ofthe LED arrays 601, 602, and 603, illustrating that LED array 601 isrotated about an axis parallel to the x-axis and that LED arrays 602 and603 are rotated about an axis parallel to the y-axis. FIG. 6Billustrates a schematic view of the LED arrays 601, 602, and 603 in thex-y plane. Views of the LED arrays 601, 602, and 603 in a projectorassembly 600 are illustrated in FIG. 6C in the y-z plane and in FIG. 6Din the x-z plane.

The projector assembly 600 illustrated in FIGS. 6A-6D may beneficiallytake advantage of the perpendicular arrangement between LED array 601and LED arrays 602 and 603. For example, LED array 601 may project afirst 2-dimensional image where a first axis of the image corresponds tothe array axis of and a second axis of the image corresponds to an axisorthogonal to the rotation axis, which may be parallel to the arrayaxis, as illustrated in FIG. 6A. Meanwhile, LED arrays 602 and/or 603may similarly generate a second 2-dimensional image in a similar way,though the axis of rotation of LED arrays 602 and 603 is perpendicularto that of LED array 601. In embodiments, the first two-dimensionalimage and the second two-dimensional image may overlap at an imageplane.

FIG. 7A illustrates another embodiment of an LED array 705 includingdistinct sets of LEDs of three different colors on a support structure710, such as a movable actuator. For example, set 715 may correspond toa set of LED elements outputting red light (e.g., including light havinga wavelength of about 650 nm). Set 720 may correspond to a set of LEDelements outputting green light (e.g., including light have a wavelengthof about 520 nm). Set 725 may correspond to a set of LED elementsoutputting blue light (e.g., including light have a wavelength of about450 nm).

Such a configuration may be useful for generating separate single-colorimages, which may be subsequently combined to generate a full colorimage. In some embodiments, the LEDs of the different LED sets 715, 720,and 725 may have corresponding LED elements in each of the other LEDsets. For example, LED element 730 may correspond to an LED elementgenerating red light for a particular pixel of an image, LED element 735may correspond to an LED element generating green light for theparticular pixel of the image, and LED element 740 may correspond to anLED element generating blue light for the particular pixel of the image.The single-color images may be combined using a variety of lightdirection and focusing techniques that may utilize one or more lenses,mirrors, fiber optic elements, waveguide elements, and/or diffractiveelements, for example.

For example, FIG. 7B illustrates one embodiment of components of aprojector assembly for generating spatially distinct images of distinctsets of LEDs 715, 720, and 725. In FIG. 7B, lenslet array 745 is shownfor initially focusing and spatially separating light from the differentLED sets 715, 720, and 725. Optical element 750 is illustrated as asingle focusing lens, but a set of imaging optics may be alternativelyused in place of optical element 750, such as a set of imaging opticsincluding one or more lenses or mirrors that serve to collimate,converge, or diverge the light in order to generate an image. Afterfocusing, the light may be recombined using additional optical elementsin order to combine the light to generate a full color image. It will beappreciated that the LED array 705 may be rotated about an axis parallelto the x-axis in FIG. 7B so that the different LED sets 715, 720, and725 can have their outputs adjusted to generate a 2-dimensional image,as described above.

FIG. 8 provides an overview of an example embodiment of a method 800 forgenerating and projecting an image, such as by using a projectorassembly. At block 805, first light from an LED array is generated. Asdescribed above, the output of each LED element in the LED array may beindependently controllable, which may allow for generation of an outputpattern corresponding to a partial image.

At block 810, the first light is imaged using a set of imaging optics inorder to generate a first partial image. Imaging may include refractingor reflecting the light, for example. Imaging may make use of reflectionoptics, focusing optics, diverging optics, collimation optics, etc.Imaging may include projecting the light to a particular distance, suchas a distance corresponding to a convergence plane.

At block 815, the LED array is rotated to move the LED array to the nextposition for generation of the next partial image. Rotation of the LEDarray may be achieved by use of a rotatable actuator, such as amicroelectromechanical actuator. Although the LED array is indicated inFIG. 8 as being rotated, in some embodiments, the LED array may betranslated instead of rotated, such as by using a translatable actuator,such as a piezoelectric actuator.

At block 820, second light from the LED array is generated. Again, theoutput of each LED element may be independently controllable and theoutput may be distinct from that corresponding to the first light.

At block 825, the second light is imaged using the set of imaging opticsto generate a second partial image. Due to the rotation of the LEDarray, the second partial image may be at least partially spatiallyoffset from the first partial image. In a specific embodiment, the firstand second partial images do not overlap. In other embodiments, thefirst and second partial images at least partly overlap.

At block 830, the LED array is rotated to move the LED array to the nextposition for generation of the next partial image. At block 835 the nextlight from the LED array is generated for the next partial image. Atblock 840 the next light is imaged using the set of imaging optics togenerate the next partial image, which may be at least partially offsetfrom the first and second partial images.

Optionally, blocks 830, 835, and 840 may be repeated one or more timesin order to generate a full image comprising a plurality of partialimages. For example, blocks 830, 835, and 840 may be repeated asufficient number of times to generate a full image including as manylines of pixels as are present in a full resolution image.

Blocks 830, 835, and 840 may also be repeated continuously in order togenerate a sequence of full images, such as make up a video image. Insuch a case, at some point the LED array may be rotated back to theposition corresponding to that at which the first light from the LEDarray is generated. In embodiments, this process may occur at about 30Hz or about 60 Hz or a particular frequency corresponding to a refreshor frame rate of a video display output.

It will be appreciated that for embodiments including multiple LEDarrays, method 800 may be independently used for each of the multipleLED arrays. In this way, each of the multiple LED arrays mayindependently generate a full image and or sequence of full images.

FIG. 9 provides an overview of an example embodiment of a method 900 forgenerating and projecting images, such as by using a projector assemblythat includes an LED array on a translatable actuator. At block 905,first light from an LED array is generated. As described above, theoutput of each LED element in the LED array may be independentlycontrollable, which may allow for generation of an output patterncorresponding to a partial image.

At block 910, the first light is imaged using a set of imaging optics inorder to generate a first partial image. Imaging may include refractingor reflecting the light, for example. Imaging may make use of reflectionoptics, focusing optics, diverging optics, collimation optics, etc.Imaging may include projecting the light to a particular distance, suchas a distance corresponding to a convergence plane.

At block 915, the LED array is rotated to move the LED array to the nextposition for generation of the next partial image. Rotation of the LEDarray may be achieved by use of a rotatable actuator, such as amicroelectromechanical actuator. Although the LED array is indicated inFIG. 9 as being rotated, in some embodiments, the LED array may betranslated instead of rotated, such as by using a translatable actuator,such as a piezoelectric actuator for generating the next partial image.

At block 920, second light from the LED array is generated. Again, theoutput of each LED element may be independently controllable and theoutput may be distinct from that corresponding to the first light.

At block 925, the second light is imaged using the set of imaging opticsto generate a second partial image. Due to the rotation of the LEDarray, the second partial image may be at least partially spatiallyoffset from the first partial image. In a specific embodiment, the firstand second partial images do not overlap. In other embodiments, thefirst and second partial images at least partly overlap. At block 930,the LED array is rotated to move the LED array to the next position forgeneration of the next partial image.

At block 935 the next light from the LED array is generated for the nextpartial image. At block 940 the next light is imaged using the set ofimaging optics to generate the next partial image, which may be at leastpartially offset from the first and second partial images. At block 945,the LED array is rotated to move the LED array to the next position forgeneration of the next partial image.

At block 950, the method may branch back to block 935 in order to repeatblocks 935, 940, and 945 if the composite image is incomplete. Block935, 940, and 945 may be repeated one or more times in order to generatethe composite image.

If the composite image is complete, block 950 may instead branch toblock 955. At block 955, the LED array is translated to the nextposition using a translatable actuator, such as a piezoelectric actuatoror a microelectromechanical actuator. With the LED array positioned in atranslated position, the process may be repeated in order to generate asecond composite image, which may be at least partially spatially offsetfrom the previously generated composite image.

It will be appreciated that method 900 may be repeated continuously inorder to generate a sequence of composite images, such as make up videoimages. In such a case, at some point the LED array may be translatedback to the position corresponding to that at which the first compositeimage is generated. In embodiments, this process may occur at about 30Hz or about 60 Hz or a particular frequency corresponding to a refreshor frame rate of a video display output.

FIG. 10 provides an overview of imaging light from an LED array whileretaining directional information according to one embodiment. LED array1005 generates light 1010 that is spatially separated by one or morelens elements 1015 and then refocused using a set of imaging optics1020, depicted here as a single focusing lens. The lens elements 1015and set of imaging optics 1020 optionally allow the output light toretain the directional information of the light generated by the LEDarray 1005.

Alternatively, set of imaging optics 1020 may include one or moreelectro-optic elements, such as elements for modulating, controlling, orretaining a phase of the light generated by the LED array. It will beappreciated that by retaining and/or controlling two or more ofdirection, amplitude, and phase of the light generated by the LED array,a multi-dimensional light field may be generated as the output of theoptical configuration, such as where the direction that the light isobserved from may impact the intensity of the light.

It is also understood that the examples and embodiments described hereinare for illustrative purposes only and that various modifications orchanges in light thereof will be suggested to persons skilled in the artand are to be included within the spirit and purview of this applicationand scope of the appended claims.

What is claimed is:
 1. A projector assembly, comprising: a first lightemitting diode (LED) array, wherein the first LED array has a firstarray axis, wherein the first LED array includes a first plurality ofLEDs arranged along the first array axis, and wherein the firstplurality of LEDs are individually addressable; a first rotatableactuator supporting the first LED array, wherein the first rotatableactuator has a first rotation axis, and wherein the first rotation axisand the first array axis are parallel; a second LED array, wherein thesecond LED array has a second array axis perpendicular to the firstarray axis, wherein the second LED array includes a second plurality ofLEDs arranged along the second array axis, and wherein the secondplurality of LEDs are individually addressable; a second rotatableactuator supporting the second LED array, wherein the second rotatableactuator has a second rotation axis, and wherein the second rotationaxis and the second array axis are parallel; a collimator positioned inoptical communication with the first LED array and the second LED arrayfor collimating light emitted from the first plurality of LEDs, thesecond plurality of LEDs, or both the first plurality of LEDs and thesecond plurality of LEDs; and a set of imaging optics positioned inoptical communication with the collimator for focusing collimated lightfrom the collimator and forming an image at an image plane, wherein theimage includes a first axis and a second axis, wherein the first axiscorresponds to a direction parallel to the first array axis, and whereinthe second axis corresponds to a direction parallel to the second arrayaxis.
 2. The projector assembly of claim 1, wherein the first axis isorthogonal to the second rotation axis, and wherein the second axis isorthogonal to the first rotation axis.
 3. The projector assembly ofclaim 1, further comprising: a translatable actuator for generating arelative translation between the collimator and the first and second LEDarrays.
 4. The projector assembly of claim 3, wherein the translatableactuator is configured to translate the first and second LED arrays to aplurality of positions.
 5. The projector assembly of claim 3, whereinthe translatable actuator is configured to translate the collimator andset of imaging optics to a plurality of positions.
 6. The projectorassembly of claim 1, wherein the first LED array comprises aone-dimensional LED array.
 7. The projector assembly of claim 1, whereinthe first LED array comprises a first one-dimensional LED array and thesecond LED array comprises a second one-dimensional LED array.
 8. Theprojector assembly of claim 1, wherein the first LED array comprises atwo-dimensional LED array.
 9. The projector assembly of claim 1, whereinthe first LED array comprises a first two-dimensional LED array and thesecond LED array comprises a second two-dimensional LED array.
 10. Theprojector assembly of claim 1, wherein the first LED array comprises aone-dimensional LED array, and wherein the second LED array comprises atwo-dimensional LED array.
 11. The projector assembly of claim 1,further comprising: a diffractive optical element positioned in opticalcommunication with the set of imaging optics for receiving the image andgenerating diffracted light; and a waveguide positioned in opticalcommunication with the diffractive optical element for receiving thediffracted light and transmitting the diffracted light by total internalreflection.
 12. The projector assembly of claim 1, wherein each LED ofthe first and second plurality of LEDs has an independently controllableoutput amplitude.
 13. A method of projecting images, the methodcomprising: generating a first composite image using a projectorassembly comprising a first light emitting diode (LED) array and asecond LED array, wherein generating the first composite image includesprojecting first light produced by the first LED array, rotating thefirst LED array, and projecting second light produced by the first LEDarray; and generating a second composite image using the projectorassembly by projecting third light produced by the second LED array,rotating the second LED array, and projecting fourth light produced bythe second LED array, wherein the first composite image and the secondcomposite image at least partially spatially overlap.
 14. The method ofclaim 13, wherein the second LED array is oriented perpendicular to thefirst LED array.
 15. The method of claim 13, further comprising:translating the first LED array and the second LED array to a firsttranslated position; generating a third composite image using theprojector assembly with the first and second LED arrays at the firsttranslated position, wherein generating the third composite imageincludes projecting fifth light produced by the first LED array,rotating the first LED array, and projecting sixth light produced by thefirst LED array; and generating a fourth composite image using theprojector assembly with the first and second LED arrays at the firsttranslated position, wherein generating the fourth composite imageincludes projecting seventh light produced by the second LED array,rotating the second LED array, and projecting eighth light produced bythe second LED array, wherein the third composite image and the fourthcomposite image at least partially spatially overlap, and wherein thethird and fourth composite images are spatially offset from the firstand second composite images.
 16. The method of claim 15, wherein thefirst and second composite images correspond to images of a first depthplane and wherein the third and fourth composite images correspond toimages of a second depth plane.
 17. The method of claim 15, furthercomprising: diffracting light corresponding to one or more of the firstcomposite image or the second composite image using a first diffractiveoptical element to generate first diffracted light; transmitting thefirst diffracted light by total internal reflection using a firstwaveguide; diffracting light corresponding to one or more of the thirdcomposite image or the fourth composite image using a second diffractiveoptical element to generate second diffracted light; and transmittingthe second diffracted light by total internal reflection using a secondwaveguide.
 18. The method of claim 13, wherein the projector assemblyincludes: the first LED array, wherein the first LED array has a firstarray axis, wherein the first LED array includes a first plurality ofLEDs arranged along the first array axis, and wherein the firstplurality of LEDs are individually addressable; a first rotatableactuator supporting the first LED array, wherein the first rotatableactuator has a first rotation axis, and wherein the first rotation axisand the first array axis are parallel; the second LED array, wherein thesecond LED array has a second array axis, wherein the second LED arrayincludes a second plurality of LEDs arranged along the second arrayaxis, and wherein the second plurality of LEDs are individuallyaddressable; a second rotatable actuator supporting the second LEDarray, wherein the second rotatable actuator has a second rotation axis,and wherein the second rotation axis and the second array axis areparallel; a collimator positioned in optical communication with thefirst LED array and the second LED array for collimating light emittedfrom the first plurality of LEDs, the second plurality of LEDs, or boththe first plurality of LEDs and the second plurality of LEDs; and a setof imaging optics positioned in optical communication with thecollimator for focusing collimated light from the collimator and formingan image at an image plane.
 19. The method of claim 18, wherein thesecond array axis is perpendicular to the first array axis.
 20. A methodof projecting images, the method comprising: creating a first partialimage using a projector assembly comprising a first light emitting diode(LED) array and a second LED array, wherein creating the first partialimage includes generating a first light using the first LED array at afirst position; rotating the first LED array to a second position; andcreating a second partial image using the projector assembly, whereincreating the second partial image includes generating a second lightusing the first LED array at the second position, and wherein the firstpartial image and the second partial image are spatially offset andtogether form a first composite image; creating a third partial imageusing the projector assembly, wherein creating the third partial imageincludes generating a third light using the second LED array at a thirdposition; rotating the second LED array to a fourth position; andcreating a fourth partial image using the projector assembly, whereincreating the fourth partial image includes generating a fourth lightusing the second LED array at the fourth position, and wherein the thirdpartial image and the fourth partial image are spatially offset andtogether form a second composite image.
 21. The method of claim 20,wherein the first composite image and the second composite image atleast partially spatially overlap.
 22. The method of claim 20, whereinthe projector assembly includes: the first LED array, wherein the firstLED array has a first array axis, wherein the first LED array includes afirst plurality of LEDs arranged along the first array axis, and whereinthe first plurality of LEDs are individually addressable; a firstrotatable actuator supporting the first LED array, wherein the firstrotatable actuator has a first rotation axis, and wherein the firstrotation axis and the first array axis are parallel; the second LEDarray, wherein the second LED array has a second array axisperpendicular to the first array axis, wherein the second LED arrayincludes a second plurality of LEDs arranged along the second arrayaxis, and wherein the second plurality of LEDs are individuallyaddressable; a second rotatable actuator supporting the second LEDarray, wherein the second rotatable actuator has a second rotation axis,and wherein the second rotation axis and the second array axis areparallel; a collimator positioned in optical communication with thefirst LED array and the second LED array for collimating light emittedfrom the first plurality of LEDs, the second plurality of LEDs, or boththe first plurality of LEDs and the second plurality of LEDs; and a setof imaging optics positioned in optical communication with thecollimator for focusing collimated light from the collimator and formingan image at an image plane.
 23. The method of claim 22, wherein eachcomposite image includes a first axis and a second axis, wherein thefirst axis corresponds to a direction parallel to the first array axis,and wherein the second axis corresponds to a direction parallel to thesecond array axis.
 24. The method of claim 20, further comprising:translating the first LED array and the second LED array to a firsttranslated position; creating a third composite image using theprojector assembly with the first and second LED arrays at the firsttranslated position; and creating a fourth composite image using theprojector assembly with the first and second LED arrays at the firsttranslated position, wherein the third and fourth composite images arespatially offset from the first and second composite images.
 25. Themethod of claim 24, wherein the first and second composite imagescorrespond to images of a first depth plane and wherein the third andfourth composite images correspond to images of a second depth plane.26. The method of claim 24, wherein the projector assembly comprises: afirst diffractive optical element positioned to receive the first andsecond composite images and generate first diffracted light; a firstwaveguide positioned to receive the first diffracted light and transmitthe first diffracted light by total internal reflection; a seconddiffractive optical element positioned to receive the third and fourthcomposite images and generate second diffracted light; and a secondwaveguide positioned to receive the second diffracted light and transmitthe second diffracted light by total internal reflection.